Getac Technology Corporation RX10RFID Manual De Usuario
SLOS743K – AUGUST 2011 – REVISED APRIL 2014
6.3.1
Supply Arrangements
Regulator Supply Input: V
IN
The positive supply at V
IN
(pin 2) has an input voltage range of 2.7 V to 5.5 V. V
IN
provides the supply
input sources for three internal regulators with the output voltages V
DD_RF
, V
DD_A
, and V
DD_X
. External
bypass capacitors for supply noise filtering must be used (per reference schematics).
NOTE
V
IN
must be the highest voltage supplied to the TRF7970A.
RF Power Amplifier Regulator: V
DD_RF
The V
DD_RF
(pin 3) regulator is supplying the RF power amplifier. The voltage regulator can be set for
either 5-V or 3-V operation. External bypass capacitors for supply noise filtering must be used (per
reference schematics). When configured for 5-V manual-operation, the V
reference schematics). When configured for 5-V manual-operation, the V
DD_RF
output voltage can be set
from 4.3 V to 5 V in 100-mV steps. In 3-V manual-operation, the output can be programmed from 2.7 V to
3.4 V in 100-mV steps. The maximum output current capability for 5-V operation is 150 mA and for 3-V
operation is 100 mA.
3.4 V in 100-mV steps. The maximum output current capability for 5-V operation is 150 mA and for 3-V
operation is 100 mA.
Analog Supply Regulator: V
DD_A
Regulator V
DD_A
(pin 1) supplies the analog circuits of the device. The output voltage setting depends on
the input voltage and can be set for 5-V and 3-V operation. When configured for 5-V manual-operation,
the output voltage is fixed at 3.4 V. External bypass capacitors for supply noise filtering must be used (per
reference schematics). When configured for 3-V manual-operation, the V
the output voltage is fixed at 3.4 V. External bypass capacitors for supply noise filtering must be used (per
reference schematics). When configured for 3-V manual-operation, the V
DD_A
output can be set from 2.7 V
to 3.4 V in 100-mV steps (see
).
Note: the configuration of V
DD_A
and V
DD_X
regulators are not independent from each other. The V
DD_A
output current should not exceed 20 mA.
Digital Supply Regulator: V
DD_X
The digital supply regulator V
DD_X
(pin 32) provides the power for the internal digital building blocks and
can also be used to supply external electronics within the reader system. When configured for 3-V
operation, the output voltage can be set from 2.7 to 3.4 V in 100-mV steps. External bypass capacitors for
supply noise filtering must be used (per reference schematics).
operation, the output voltage can be set from 2.7 to 3.4 V in 100-mV steps. External bypass capacitors for
supply noise filtering must be used (per reference schematics).
Note: the configuration of the V
DD_A
and V
DD_X
regulators are not independent from each other. The V
DD_X
output current should not exceed 20 mA.
The RF power amplifier regulator (V
DD_RF
), analog supply regulator (V
DD_A
) and digital supply regulator
(V
DD_X
) can be configured to operate in either automatic or manual mode described in
. The
automatic regulator setting mode ensures an optimal compromise between PSRR and the highest
possible supply voltage to ensure maximum RF power output.
possible supply voltage to ensure maximum RF power output.
By default, the regulators are set in automatic regulator setting mode. In this mode, the regulators are
automatically set every time the system is activated by setting EN input High or each time the automatic
regulator setting bit, B7 in register 0x0B is set to a 1. The action is started on the 0 to 1 transition. This
means that, if the user wants to re-run the automatic setting from a state in which the automatic setting bit
is already high, the automatic setting bit (B7 in register 0x0B) should be changed: 1-0-1.
automatically set every time the system is activated by setting EN input High or each time the automatic
regulator setting bit, B7 in register 0x0B is set to a 1. The action is started on the 0 to 1 transition. This
means that, if the user wants to re-run the automatic setting from a state in which the automatic setting bit
is already high, the automatic setting bit (B7 in register 0x0B) should be changed: 1-0-1.
By default, the regulator setting algorithm sets the regulator outputs to a "Delta Voltage" of 250 mV below
V
V
IN
, but not higher than 5 V for V
DD_RF
and 3.4 V for V
DD_A
and V
DD_A
. The "Delta Voltage" in automatic
regulator mode can be increased up to 400 mV (for details, see bits B0 to B2 in register 0x0B).
16
Detailed Description
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